This invention relates to methods and apparatus for conditioning textile fibers and particularly raw cotton fibers or blends of natural and synthetic fibers as the fibers are collected from individual ones of a plurality of bales of the fibers.
It is recognized in the textile industry that the moisture content of textile fibers can either beneficially or adversely affect the physical properties of the fibers. For example, cotton fibers processed at a moisture content between about 4% and 8%, are of maximum strength and elasticity. Cotton fibers processed at lower moisture contents, particularly below 4%, tend to be brittle and break, creating an excessive amount of broken fibers, leading to poor processing of the fibers into yarn, for example, and excessive waste of raw material and excessive quantities of "cotton dust" in the ambient environment of the processing facility. Waste and cotton dust raise the cost of environmental controls, cleaning of equipment and facilities, and disposal. Because cotton is an agricultural product, each bale contains fibers of different characteristics, in particular moisture content. The moisture level can vary even within a single bale, depending upon the environmental conditions in which the cotton is baled and stored, but baled cotton generally has a moisture level of about 3-4%. Accordingly, in the prior art, some processing facilities have attempted to control the humidity of the ambient environment of the processing facility through the use of moisture atomizers located externally of the processing equipment, but within the processing facility opening room and bale take-up, for example.
In modern fiber processing facilities, it has become common practice to enhance the speed of introduction of fibers into the processing facility through the use of a "lay down". This technique involves aligning a plurality of bales of the fibers so that the top surface of each bale is disposed substantially within a common horizontal plane. A vacuum device is passed over the exposed fibers of the top surfaces of the bales such that a small portion of the fibers of each bale is drawn from the bale, entrained in air and conveyed to further processing stations. The bales of a lay down are held in a warehouse or the like for a period of time, but even humidifying the warehouse has not adequately adjusted the humidity of the bales to a desired level before the bales are placed in a lay down. This process requires long times and cost, as well.
In similar manner, the trash content of bales may vary widely and/or the fibers may have some undesirable foreign material associated therewith and which adversely affects its processability. It has been known heretofore, for example, that frequently the moisture content of cotton fibers must be optimized in order to achieve optimum cleaning and processing. Accordingly, the humidity of the ambient air has been controlled in some cotton processing plants, and/or water has been added directly to the cotton fibers while yet baled or as they are removed from bales for processing. However, if too much moisture is added to the fibers or the moisture is added too rapidly (unbound moisture) the fibers tend to stick to one another, or to trash mixed in the bales, or to the processing equipment. In order to provide usable cotton for textiles, preferably a maximum amount of the trash is removed before the fibers are spun. The trash removal process, however, should not adversely affect the fibers themselves.
It has also been suggested heretofore that one can add various other fiber treating agents to the cotton fibers to enhance the ease and/or efficiency with which the fibers are collected, cleaned of trash, carded, and eventually spun into yarns. In the prior art, attempts also have been made to apply water and/or oversprays onto the fibers while they are entrained in air in a transfer duct, for example. In these fiber-treating techniques, the oversprays have comprised vegetable oils as lubricants, for example. Unfortunately, these oils, and other oversprays tend to collect on the equipment and accumulate cotton dust and dirt and other trash from the environment, requiring frequent cleaning of the fiber-handling equipment. Also, once applied to the cotton, the oils adversely affect the dyeability of the fibers. Over sprays as currently known to exist in the art fail to effectively perform their desired intended result, at least partly due to their inability to drive the moisture into the fibers. Rather, over sprays tend to discourage moisture absorption and thus accumulate surface moisture only and fail to enhance the processibility of the fibers.
U.S. Pat. No. 4,554,708 issued to Leifeld, et al discloses a system for collecting cotton from bales in which a truck travels back and forth along a set of rails adjacent to a plurality of bales of cotton. A bale opener assembly is cantilevered over the bales. As the truck moves alongside the bales, the bale opener assembly progressively removes the topmost fibers from the bales by vacuum suction. A liquid is sprayed downwardly in a conical pattern onto the exposed top layer of a bale of cotton fibers from nozzles mounted upon the trailing, side of the assembly. Provision is made for switching between different spray nozzles depending upon the direction of movement of the assembly. Otherwise, the disclosed system provides no control of the sprayed liquid so that this system is little more than another form of the prior art over spray technique. Further, this prior art system requires that the source of the liquid being sprayed be mounted on the truck, thereby limiting the quantity of liquid available to the system, resulting in inordinate down time for refills, etc. This factor defeats the primary purpose of a lay down, namely, saving of time.
The economics in the textile industry require the treatment of very large volumes of fibers. Any percentage of waste of raw fibers or treatment materials, such as conditioning agents, is of extreme economic significance. Moreover, excess application of conditioning agents causes fibers to agglomerate due to the presence of the excess liquid conditioning agent on the surface of the fibers. Disentangling these fibers during subsequent processing of the fibers is made more difficult, results in poor fiber alignment, poor cleaning, loss of fibers and unnecessary wear upon the processing equipment. In addition, the agglomerated fibers tend to entrap trash particles therein and increase the quantity of trash that continues with the cotton fibers into subsequent processing operations. This excess trash reduces the quality of the finished product and increases the wear on the production equipment. Alternatively, if the trash is aggressively removed, large amounts of cotton fibers are broken or lost with the trash. In the prior art attempts to enhance the processability of fibers, especially cotton fibers, there has been a failure to ensure retention of the applied moisture in that the moisture applied by the known prior art systems and methods tends to be lost as the fibers are conveyed (via air entrainment) through the ductwork and various work stations of the processing facility. Thus, in the prior art, even though a given moisture content of the fibers is initially established at the infeed station of the fibers to the processing facility, this moisture content is lost before the fibers are fully processed. In fact, the moisture content of the fibers decreases continually at the fibers are conveyed from station to station in the processing facility.
It is therefore an object of the present invention to provide a system for controlling the conditioning of textile fibers as the fibers are collected from one or more aligned bales of the fibers and prior to entrainment of the fibers for their transport into a textile mill, for example.
It is another object to enhance the control of the addition of a liquid conditioning agent to textile fibers to ensure proper take-up and retention of the desired moisture by the fibers.
It is also an object of the present invention to provide a system for monitoring the levels of conditioning agents, moisture, trash, sugar, polyester and other materials in textile fibers or blends thereof by adding tracers selective to such materials and measuring the amount of the tracers at a location in a flowing stream of the fibers and employing the information obtained to control the addition of water and/or a conditioning agent to the fibers prior to their being entrained for conveyance to a processing facility.
It is another object of the present invention to provide for the selective introduction of a choice of conditioning agents to fibers at or near the initial introduction of the fibers to a processing facility.
It is another object of the present invention to provide a method for enhancing the processability of textile fibers.
These and other objects of the present invention will become apparent upon a consideration of the drawings referred to hereinafter and a complete description thereof, plus the claims appended hereto.